Improvement in millstone-dressing machines



J. B. HARRIS.

Mill-StoneDressing-Machines. I ."N 137,3 4 PatentedApril1,1873.

Wtnesses: Inventor.

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AM P/IOTOLITHOGRAFli/C ca Mflassogwsls macsss) UNITED STATES PATENT Orrrcn.

.TOHNB. nAnnIs, on OTTAWA, ILLINOIS.

IMPROVEMENT IN IVlILLSTONE-DRESSING MACHINES.

Specification forming part of Letters Patent No. 137,364, dated April 1, 1873 application filed February 10, 1873.

Nature and Objects of the Invention.

The first part of my invention relates to that class of millstone-dressing machines in which an ordinary-shaped mill-pick is inserted into a handle which is worked and guided by the help of a regulating apparatus; and

V consists in a novel feeding device which has an accurate action, and is under the complete control of the operator.

Description of the Accompanying Drawing.

Figure 1 is a plan of a machine embodying my invention. Fig. 2 is an elevation, showing that end of the machine which is at the bottom in Fig. 1. Fig. 3 is an elevation, showing in part that side which is at the right hand in Fig. 1. 1

General Description.

A is the base, made of wood or other suitable material, and is about twenty-two inches long and twelve inches wide. On top of this base A are placed two parallel ways, B, which are about five inches apart and extend about two-thirds the length of the base A. On top of these ways and connected therewith by V shaped grooves I place a suitable frame, 0, in which frame I place a horizontal feed-screw, d, by suitable bearings. On the outer end of this feed-screw d I attach a ratchet-wheel, e, by means of which, with the pawl f and lever g, the screw d is made to rotate. On the side, near this feed-screw d, and running parallel with it, is securely attached a guide-rod, h, upon which rod is placed a slide, i, one end of which rests in the thread of the feed-screw d. A common mill-pick handle, J, having a pick, K, inserted into it in the ordinary way, has at the other end a pivot, L, attached to it. On top of the slide 2' is a recess or socket in which socket the pivot L at the end of the handle J is placed when in use, but without any fastening, it being'held in place and position by the hand of the operator so that it can be taken 011' at any time. On the outer end of the frame 0, and under the lever g, Iplace an adjustable stop or rest, m, which is adjusted by a screw passing through a slot so that the pawl f will engage each tooth or notch on the ratchetwheel e, or each second or third one, or as many as may be desired. The lever g is pivoted at n, as shown in Fig. 3, and, when the screw d is to be moved, is raised by the fingers of the right hand, which rests on the end of the pickhandle J. The lever g and pawl f are returned by their own weight. On top of the base A I place additional ways or a track, 0 O, upon which track, and supported by flanged wheels on suitable axles, is a block or elbowrest, P, which rest is designed to be moved forward and backward on such track. The pick-head K is shaped like a common hand mill-pick, and is made of cast or malleable iron. A slit in each end receives the steel cutters q g, which are suitably tempered and are held in place by the screws 1' 1". When the cutters are worn down to the cast head they are taken out by removing the screws 1" r, and new ones inserted, the cost of which is comparatively small.

The manner of working this machine is as follows: The dresser is placed on the face of the stone, parallel with the land to be dressed. When placed in the proper position the operator grasps that part of the handle J which rests on the slidei with his right hand, and places the other at the outer end near the pick K, the left fore-arm resting on the block or rest P. The handle J is then moved up and down by the left hand, striking the pick against the stone, at the same time moving the handle J and the folding device with it laterally across the base A, it being guided by the ways B. When a crack of snfficient length is made the lever g is raised by extending the fingers of the right hand, which moves the feed-screw 61, when the thread of the screw, acting upon the slide t, advances the pick K the proper distance for a new crack, the distance for it to move having been first adjusted by the stop or rest m under the lever g. The operation is then repeated, and continued until the feed-screw d has been traversed its entire length or the land is dressed, when the slide t is raised out of the feed-screw d, and returned to its original pobination with the pick K and the handle J, sition. The machine is then moved to a new substantially as described. land, ready for a fresh operation, and so on, 2. The pickK and handle J in combination until the entire stone is dressed. with the resting-block P and the feeding de- What I claim as my invention, and desire vice, constructed and operated substantially to secure by Letters Patent, isas described.

1. The feeding device, consisting of the fol- Witnesses: JOHN B. HARRIS. lowing parts: The frame 0, feed-screw d, lever EDWARD Roma, slide d, guide-rod h, and the rest m, in com- 1?. W. STOCKSLEGER. 

